Re: [PATCH RESEND v4 2/2] thermal: hisilicon: add new hisilicon thermal sensor driver

[Xinwei Kong <kong.kongxinwei@hisilicon.com>]

On 2015/5/12 9:29, Eduardo Valentin wrote:
> Dear Kongxinwei,
> 
> 
> Apologize for late answer. I really missed this one. Let's make it for
> the next merge window!
> 
> Please find a couple of comments as follows.
> 
> 
> On Mon, May 04, 2015 at 10:52:20AM +0800, Xinwei Kong wrote:
>> From: kongxinwei <kong.kongxinwei@hisilicon.com>
>>
>> This patch adds the support for hisilicon thermal sensor, within
>> hisilicon SoC. there will register sensors for thermal framework
>> and use device tree to bind cooling device.
>>
>> Signed-off-by: Leo Yan <leo.yan@linaro.org>
>> Signed-off-by: kongxinwei <kong.kongxinwei@hisilicon.com>
>> ---
>>  drivers/thermal/Kconfig        |   8 +
>>  drivers/thermal/Makefile       |   1 +
>>  drivers/thermal/hisi_thermal.c | 437 +++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 446 insertions(+)
>>  create mode 100644 drivers/thermal/hisi_thermal.c
> 
> 
> Please, make sure you have a clean ./checkpatch.pl --strict output.
> Today, in this version, I see the following summary:
> 
> # ./scripts/checkpatch.pl --strict /tmp/a
> total: 0 errors, 2 warnings, 7 checks, 455 lines checked
> 
> /tmp/a has style problems, please review.
> 
> If any of these errors are false positives, please report
> them to the maintainer, see CHECKPATCH in MAINTAINERS.
> 
> Can you please clean them up?
> 
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index af40db0..81aee01 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -136,6 +136,14 @@ config THERMAL_EMULATION
>>  	  because userland can easily disable the thermal policy by simply
>>  	  flooding this sysfs node with low temperature values.
>>  
>> +config HISI_THERMAL
>> +	tristate "Hisilicon thermal driver"
>> +	depends on ARCH_HISI && CPU_THERMAL && OF
>> +	help
>> +	  Enable this to plug hisilicon's thermal sensor driver into the Linux
>> +	  thermal framework. cpufreq is used as the cooling device to throttle
>> +	  CPUs when the passive trip is crossed.
>> +
>>  config IMX_THERMAL
>>  	tristate "Temperature sensor driver for Freescale i.MX SoCs"
>>  	depends on CPU_THERMAL
>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>> index fa0dc48..08ae7ac 100644
>> --- a/drivers/thermal/Makefile
>> +++ b/drivers/thermal/Makefile
>> @@ -39,3 +39,4 @@ obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
>>  obj-$(CONFIG_INT340X_THERMAL)  += int340x_thermal/
>>  obj-$(CONFIG_ST_THERMAL)	+= st/
>>  obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
>> +obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
>> new file mode 100644
>> index 0000000..255c71b
>> --- /dev/null
>> +++ b/drivers/thermal/hisi_thermal.c
>> @@ -0,0 +1,437 @@
>> +/*
>> + * Hisilicon thermal sensor driver
>> + *
>> + * Copyright (c) 2014-2015 Hisilicon Limited.
>> + * Copyright (c) 2014-2015 Linaro Limited.
>> + *
>> + * Xinwei Kong <kong.kongxinwei@hisilicon.com>
>> + * Leo Yan <leo.yan@linaro.org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>> + * kind, whether express or implied; without even the implied warranty
>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/cpufreq.h>
> 
> I don't see why you need this header.
> 
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/mfd/syscon.h>
> 
> neither this
> 
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
> 
> or this
> 
>> +#include <linux/slab.h>
>> +#include <linux/thermal.h>
>> +#include <linux/types.h>
>> +
>> +#include "thermal_core.h"
> 
> 
> Please review the above includes. Leave only those you are using.
> 
>> +
>> +#define TEMP0_TH			(0x4)
>> +#define TEMP0_RST_TH			(0x8)
>> +#define TEMP0_CFG			(0xC)
>> +#define TEMP0_EN			(0x10)
>> +#define TEMP0_INT_EN			(0x14)
>> +#define TEMP0_INT_CLR			(0x18)
>> +#define TEMP0_RST_MSK			(0x1C)
>> +#define TEMP0_VALUE			(0x28)
>> +
>> +#define HISI_TEMP_BASE			(-60)
>> +#define HISI_TEMP_RESET			(100000)
>> +
>> +#define HISI_MAX_SENSORS		4
>> +
>> +struct hisi_thermal_sensor {
>> +	struct hisi_thermal_data *thermal;
>> +	struct thermal_zone_device *tzd;
>> +	const struct thermal_trip *trip;
>> +
>> +	uint32_t id;
>> +	uint32_t thres_temp;
>> +	uint32_t reset_temp;
> 
> reset_temp is never used in this driver.
> 
>> +};
>> +


Ok, I will fix it and pay attention to the detail format. thx.


>> +struct hisi_thermal_data {
>> +	struct mutex thermal_lock;
>> +	struct platform_device *pdev;
>> +	struct clk *clk;
>> +
>> +	int irq, irq_bind_sensor;
>> +	bool irq_enabled;
>> +
>> +	unsigned int sensors_num;
>> +	long sensor_temp[HISI_MAX_SENSORS];
>> +	struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
> 
> Does it make sense to make sensor_temp part of hisi_thermal_sensors?
> 
> Then you would access it through sensors.sensor_temp
> 

I understand this way, use and test it

>> +
>> +	void __iomem *regs;
>> +};
>> +
>> +/* in millicelsius */
>> +static inline int _step_to_temp(int step)
>> +{
>> +	/*
>> +	 * Every step equals (1 * 200) / 255 celsius, and finally
>> +	 * need convert to millicelsius.
>> +	 */
>> +	return (HISI_TEMP_BASE + (step * 200 / 255)) * 1000;
>> +}
>> +
>> +static inline int _temp_to_step(int temp)
>> +{
>> +	return ((temp / 1000 - HISI_TEMP_BASE) * 255 / 200);
>> +}
>> +
>> +static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
>> +					 struct hisi_thermal_sensor *sensor)
>> +{
>> +	int val;
>> +
>> +	mutex_lock(&data->thermal_lock);
>> +
>> +	/* disable interrupt */
>> +	writel(0x0, data->regs + TEMP0_INT_EN);
>> +	writel(0x1, data->regs + TEMP0_INT_CLR);
>> +
>> +	/* disable module firstly */
>> +	writel(0x0, data->regs + TEMP0_EN);
>> +
>> +	/* select sensor id */
>> +	writel((sensor->id << 12), data->regs + TEMP0_CFG);
>> +
>> +	/* enable module */
>> +	writel(0x1, data->regs + TEMP0_EN);
>> +
>> +	usleep_range(3000, 5000);
>> +
>> +	val = readl(data->regs + TEMP0_VALUE);
>> +	val = _step_to_temp(val);
>> +
>> +	/* adjust for negative value */
>> +	val = (val < 0) ? 0 : val;
> 
> Why?
> 
> What does val < 0 mean here? Does it mean negative temperature or an
> error?
> 
> BTW, There is ongoing work to allow, at least representing, negative
> temperature.
> 
 consult hardware engineer to get some information which temperature range
is -40 ~ +160.  I will deal it in the next version.

> 
>> +
>> +	mutex_unlock(&data->thermal_lock);
>> +
>> +	return val;
>> +}
>> +
>> +static void hisi_thermal_bind_irq(struct hisi_thermal_data *data)
>> +{
>> +	struct hisi_thermal_sensor *sensor;
>> +
>> +	sensor = &data->sensors[data->irq_bind_sensor];
>> +
>> +	mutex_lock(&data->thermal_lock);
>> +
>> +	/* setting the hdak time */
>> +	writel(0x0, data->regs + TEMP0_CFG);
>> +
>> +	/* disable module firstly */
>> +	writel(0x0, data->regs + TEMP0_RST_MSK);
>> +	writel(0x0, data->regs + TEMP0_EN);
>> +
> 
> Sorry, I get confused when you tell me you need to disable the module
> every time you need to read temp / change irq configuration.
> 
> Is this really required?
> 

yes. Soc have four sensor. They share a series of register. If not disabling
this module, the systerm will possible produce some problem.

For example, when setting the CPU0 sensor thres_temp is 50 degree. I will plan
to set and check the GPU sensor temp, (but the gpu sensor thres_temp require
70 degree). However, GPU sensor temp is 60 degree in fact. Before change
data->regs + TEMP0_TH register, the GPU sensor will produce interrupt under
50 degree. Because GPU and CPU0 share the TEMP0_TH register, so i will disable
this module.

>> +	/* select sensor id */
>> +	writel((sensor->id << 12), data->regs + TEMP0_CFG);
>> +
>> +	/* enable for interrupt */
>> +	writel(_temp_to_step(sensor->thres_temp)
>> +			| 0x0FFFFFF00, data->regs + TEMP0_TH);
> 
> 
> nit: break after the | operator.
> 
>> +
>> +	writel(_temp_to_step(HISI_TEMP_RESET), data->regs + TEMP0_RST_TH);
>> +
>> +	/* enable module */
>> +	writel(0x1, data->regs + TEMP0_RST_MSK);
>> +	writel(0x1, data->regs + TEMP0_EN);
>> +
>> +	writel(0x0, data->regs + TEMP0_INT_CLR);
>> +	writel(0x1, data->regs + TEMP0_INT_EN);
>> +
>> +	usleep_range(3000, 5000);
>> +
>> +	mutex_unlock(&data->thermal_lock);
>> +
> nit: remove empty line.
> 
>> +}
>> +
>> +static void hisi_thermal_enable_sensor(struct hisi_thermal_data *data)
>> +{
>> +	hisi_thermal_bind_irq(data);
>> +}
>> +
>> +static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)
>> +{
>> +
>> +	mutex_lock(&data->thermal_lock);
>> +
>> +	/* disable sensor module */
>> +	writel(0x0, data->regs + TEMP0_INT_EN);
>> +	writel(0x0, data->regs + TEMP0_RST_MSK);
>> +	writel(0x0, data->regs + TEMP0_EN);
>> +
>> +	mutex_unlock(&data->thermal_lock);
>> +
> 
> nit: remove empty line.

ok. good comment

> 
>> +}
>> +
>> +static int hisi_thermal_get_temp(void *_sensor, long *temp)
>> +{
>> +	struct hisi_thermal_sensor *sensor = _sensor;
>> +	struct hisi_thermal_data *data = sensor->thermal;
>> +
>> +	int sensor_id = 0, i;
>> +	long max_temp = 0;
>> +
>> +	*temp = hisi_thermal_get_sensor_temp(data, sensor);
>> +
>> +	data->sensor_temp[sensor->id] = *temp;
>> +
>> +	for (i = 0; i < HISI_MAX_SENSORS; i++) {
>> +		if (data->sensor_temp[i] >= max_temp) {
>> +			max_temp = data->sensor_temp[i];
>> +			sensor_id = i;
>> +		}
>> +	}
>> +
>> +	data->irq_bind_sensor = sensor_id;
> 
> I believe this irq_bind_sensor needs to be protected by a lock.
> 
> You read it in t_irq context, write it here while getting temp, and read
> it in bind irq.
> 
> I still don't follow why you need it though, can you please explain?
> 
> In any case, seams to be racy, given that it is shared by the four
> sensors, but you don't lock it to use it.
> 
>> +
>> +	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%ld, thres=%d\n",
>> +		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
>> +	/*
>> +	 * Bind irq to sensor for two cases:
>> +	 *   Reenable alarm IRQ if temperature below threshold;
>> +	 *   if irq has been enabled, always set it;
>> +	 */
>> +	if (data->irq_enabled) {
>> +		hisi_thermal_bind_irq(data);
>> +		return 0;
>> +	}
>> +
>> +	if (max_temp < sensor->thres_temp) {
>> +		data->irq_enabled = true;
>> +		hisi_thermal_bind_irq(data);
>> +		enable_irq(data->irq);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
>> +	.get_temp = hisi_thermal_get_temp,
>> +};
>> +
>> +static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
>> +{
>> +	struct hisi_thermal_data *data = dev;
>> +
>> +	disable_irq_nosync(irq);
>> +	data->irq_enabled = false;
>> +
>> +	return IRQ_WAKE_THREAD;
>> +}
>> +
>> +static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
>> +{
>> +	struct hisi_thermal_data *data = dev;
>> +	struct hisi_thermal_sensor *sensor;
>> +	int i;
>> +
>> +	sensor = &data->sensors[data->irq_bind_sensor];
>> +
>> +	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
>> +		 sensor->thres_temp / 1000);
> 
> Do you really want to be printing this every time you receive an IRQ?
> 
>> +
>> +	for (i = 0; i < data->sensors_num; i++)
>> +		thermal_zone_device_update(data->sensors[i].tzd);
> 
> 
> Can you please educate me on how this chip works?
> 
> You receive a thermal alarm from the chip, does it really  mean you have
> to update all thermal zones? Or do you have a way to check which sensor
> generated the alarm irq?
> 
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int hisi_thermal_register_sensor(struct platform_device *pdev,
>> +					struct hisi_thermal_data *data,
>> +					struct hisi_thermal_sensor *sensor,
>> +					int index)
>> +{
>> +	int ret, i;
>> +
>> +	sensor->id = index;
>> +	sensor->thermal = data;
>> +
>> +	sensor->tzd = thermal_zone_of_sensor_register(&pdev->dev, sensor->id,
>> +				sensor, &hisi_of_thermal_ops);
>> +	if (IS_ERR(sensor->tzd)) {
>> +		ret = PTR_ERR(sensor->tzd);
>> +		dev_err(&pdev->dev, "failed to register sensor id %d: %d\n",
>> +			sensor->id, ret);
>> +		return ret;
>> +	}
>> +
>> +	sensor->trip = of_thermal_get_trip_points(sensor->tzd);
>> +
>> +	for (i = 0; i < of_thermal_get_ntrips(sensor->tzd); i++) {
>> +		if (sensor->trip[i].type == THERMAL_TRIP_PASSIVE) {
> 
> what if you have more than one passive trip? You just care about the
> first?
> 
>> +			sensor->thres_temp = sensor->trip[i].temperature;
> 
> Looks like you use sensor->trip only for filling thres_temp here. Does
> it make sense to use a local variable in this function, given you won't
> use sensor->trip anywhere else?
> 
>> +			break;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id of_hisi_thermal_match[] = {
>> +	{ .compatible = "hisilicon,tsensor" },
>> +	{ /* end */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, of_hisi_thermal_match);
>> +
>> +static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor,
>> +				       bool on)
>> +{
>> +	struct thermal_zone_device *tzd = sensor->tzd;
>> +
>> +	tzd->ops->set_mode(tzd,
>> +		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
>> +}
>> +
>> +static int hisi_thermal_probe(struct platform_device *pdev)
>> +{
>> +	struct hisi_thermal_data *data;
>> +	struct resource *res;
>> +	int i;
>> +	int ret;
>> +
>> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>> +	if (!data)
>> +		return -ENOMEM;
>> +
>> +	mutex_init(&data->thermal_lock);
>> +	data->pdev = pdev;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	data->regs = devm_ioremap_resource(&pdev->dev, res);
>> +	if (IS_ERR(data->regs)) {
>> +		dev_err(&pdev->dev, "failed to get io address\n");
>> +		return PTR_ERR(data->regs);
>> +	}
>> +
>> +	data->irq = platform_get_irq(pdev, 0);
>> +	if (data->irq < 0)
>> +		return data->irq;
>> +
>> +	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
>> +			hisi_thermal_alarm_irq, hisi_thermal_alarm_irq_thread,
>> +			0, "hisi_thermal", data);
>> +	if (ret < 0) {
>> +		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, data);
>> +
>> +	data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
>> +	if (IS_ERR(data->clk)) {
>> +		ret = PTR_ERR(data->clk);
>> +		if (ret != -EPROBE_DEFER)
>> +			dev_err(&pdev->dev,
>> +				"failed to get thermal clk: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	/* enable clock for thermal */
>> +	ret = clk_prepare_enable(data->clk);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
>> +		ret = hisi_thermal_register_sensor(pdev, data,
>> +					&data->sensors[i], i);
>> +		if (ret) {
>> +			dev_err(&pdev->dev,
>> +			"failed to register thermal sensor: %d\n", ret);
>> +			goto err_get_sensor_data;
>> +		}
>> +	}
>> +
>> +	hisi_thermal_enable_sensor(data);
>> +	data->irq_enabled = true;
>> +
>> +	for (i = 0; i < data->sensors_num; i++)
>> +		hisi_thermal_toggle_sensor(&data->sensors[i], true);
>> +
>> +	return 0;
>> +
>> +err_get_sensor_data:
>> +	clk_disable_unprepare(data->clk);
> 
> nit: empty line here to follow your pattern.
> 
>> +	return ret;
>> +}
>> +
>> +static int hisi_thermal_remove(struct platform_device *pdev)
>> +{
>> +	struct hisi_thermal_data *data = platform_get_drvdata(pdev);
>> +	int i;
>> +
>> +	for (i = 0; i < data->sensors_num; i++) {
>> +		struct hisi_thermal_sensor *sensor = &data->sensors[i];
>> +
>> +		hisi_thermal_toggle_sensor(sensor, false);
>> +		thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
>> +	}
>> +
>> +	hisi_thermal_disable_sensor(data);
>> +	clk_disable_unprepare(data->clk);
> 
> nit: empty line here to follow your pattern.
> 
>> +	return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int hisi_thermal_suspend(struct device *dev)
>> +{
>> +	struct hisi_thermal_data *data = dev_get_drvdata(dev);
>> +
>> +	hisi_thermal_disable_sensor(data);
>> +	data->irq_enabled = false;
>> +
>> +	clk_disable_unprepare(data->clk);
>> +
>> +	return 0;
>> +}
>> +
>> +static int hisi_thermal_resume(struct device *dev)
>> +{
>> +	struct hisi_thermal_data *data = dev_get_drvdata(dev);
>> +
>> +	clk_prepare_enable(data->clk);
>> +
>> +	data->irq_enabled = true;
>> +	hisi_thermal_enable_sensor(data);
>> +
>> +	return 0;
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(hisi_thermal_pm_ops,
>> +			 hisi_thermal_suspend, hisi_thermal_resume);
>> +
>> +static struct platform_driver hisi_thermal_driver = {
>> +	.driver = {
>> +		.name	= "hisi_thermal",
>> +		.owner  = THIS_MODULE,
>> +		.pm	= &hisi_thermal_pm_ops,
>> +		.of_match_table = of_hisi_thermal_match,
> 
> 
> nit: align on the '=' operator.
> 
>> +	},
>> +	.probe		= hisi_thermal_probe,
>> +	.remove		= hisi_thermal_remove,
>> +};
>> +
>> +module_platform_driver(hisi_thermal_driver);
>> +
>> +MODULE_AUTHOR("Xinwei Kong <kong.kongxinwei@hisilicon.com>");
>> +MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
>> +MODULE_DESCRIPTION("Hisilicon thermal driver");
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 1.9.1
>>
>>